Research Projects

More than 50% of industrial chemicals and over 20% of pharmaceutical products require introduction of chlorine or bromine atom at some point. Additionally, more than 250 FDA approved drugs currently in the market contains at least one chlorine or bromine atom. Despite such high importance, methods available for late stage halogenation (chlorination and bromination) reactions with industrially relevant sustainable halogenation sources are limited. As per ACS GCI Pharmaceutical Roundtable, only alkali metal halides and N-halosuccinimides are the 'ideal halogen sources' for halogenation reactions. Synthetic methods using these reagents for late stage incorporation of halogen atoms are limited due to their low reactivity. In this proposal we envisage the discovery of novel class of sustainable catalytic methods which could be used with the less reactive yet 'ideal halogenation sources' in late stage halogenation reactions. We plan to use S-based organocatalysts to increase the reactivity of N-halosuccinimides and aryl iodide based polarity reversal electrocatalysts for inert alkali metal halides. Our initial results with S-based organocatalysts strongly support feasibility of developing such highly reactive catalytic systems for hitherto unprecedented electrophilic halogenation reactions. Subsequently, we intend to develop flow chemical processes for these newly developed methods for safe and easy scaling up to bridge the gap between fundamental research and applied target synthesis.